Acting Inspector Luke Moore said paramedics did what they could to control the situation.

"After a brief scuffle inside the ambulance, the ambulance officers have been able to stop the ambulance on the side of the highway activate their emergency lights and their duress alarm," he said.

The officers then got out of the vehicle when they were unable to restrain the patient.

The man drove off before crashing it into a railing a short distance away.

"[The patient was] reversing back up the highway [towards] George Town before he's crashed," Acting Inspector Moore said.

The man was taken into custody by police, who then took him to hospital.

Acting Inspector Moore said there was moderate damage to the ambulance and charges are yet to be laid.

"Police are still looking into it - it's relatively early stages because we took the man straight through to the hospital we haven't had a chance to talk to him yet but we are looking at a number of possible charges to come out of this yes," he said.